JPS6186586A - Hume control system of arc furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fume control system designed to collect emissions generated during the operating stages of various melting furnaces and Nli furnaces.

The invention applies in particular to arc furnaces.

Arc furnaces are used for melting scrap and refining steel. These furnaces are typically vessels with rotatable tops having associated electrodes used as melting sources.

The furnace is supported by a tiltable base or other movable structure so that upon completion of melting or refining, molten metal can be poured into a collection ladle through a pouring spout or tapping hole in the lower portion of the vessel.

The emissions generated during operation of the arc furnace have an average value of about 1-2% of the weight of the metal injected.

Emissions are in the form of gaseous contaminants and fine particulates and are emitted during three different stages of furnace operation. The first stage in which waste is generated is during furnace filling. During filling, the top of the furnace and associated electrodes are pivoted to one side of the furnace while scrap metal and/or molten metal is added to the furnace vessel. The second stage, which generates a wide range of emissions, is the melting or refining stage where fumes exit from various orifices during melting, addition of flux or alloy paulownia material, and also during temperature determination and sampling.

The third stage of producing the discharge is the tapping stage in which molten metal is poured into a receiving pan or collection pan.

Under current environmental controls, emissions generated during arc furnace operation must not be released into the atmosphere.

Prior art methods aimed at collecting emissions generated during operation of an arc furnace fall into one of four types of methods.

The first method of furnace exhausting draws fumes through an opening in the furnace roof or through a side draft hood around the electrodes. Additional shrouds over the tap hole, electrode hole, and fill door also draw furnace fluid through these individual openings. This system does not comply with modern regulations and, moreover, does not adequately collect the fumes generated when the top is removed from the furnace for the purpose of scrap filling, nor does it collect during the tapping stage.

A second method consists of extracting the fume through the canopy of the roof of the building. The canopy is located at a distance from the Huyum outbreak site.

As a result, operating costs are high because unusually large volumes of exhaust air must be moved to achieve a sufficient factory atmosphere, and the entire exhaust must be cleaned before being discharged to the atmosphere. Therefore, for economic reasons, it is desirable to keep the volume of exhaust air to a minimum.

A third method of evacuating the plant is to properly remove the exhaust produced during furnace operation. However, complete exhaustion of a factory requires purification of a literary volume of gas. Moreover, during the exhaust operation, the factory atmosphere is polluted and dangerous to the workers.

A fourth, more recent method consists of partially enclosing the furnace in a housing that extends over the top and sides of the furnace. The dimensions of the housing are such as to allow tilting of the furnace during the tapping phase when molten metal is poured into a ladle located outside the enclosure. The housing typically includes a primary exhaust system in the upper region of the housing to collect fumes generated during operation of the furnace.

Additional auxiliary exhaust system equipment is provided adjacent to the tap point to specifically remove contaminants generated during the tap step. The main drawback of this method is that the housing does not completely enclose the ladle and therefore does not effectively remove fumes generated during dumping. Therefore,
It is inevitable that some of the fumes generated over a wide area during the hot water tapping operation will escape into the factory. Additionally, the primary and secondary exhaust systems within such housings typically operate continuously during all stages of furnace operation and must be cleaned after furnace operation before being vented to the atmosphere. is not selectively controlled to reduce the volume of gas that must be present.

It is an object of the present invention to provide an improved fume control system for a furnace, such as an arc furnace, without the above-mentioned drawbacks of the prior art methods.

According to the present invention, the collection of emissions generated during the operation of a furnace, such as an electric arc furnace, generally surrounds the furnace and the collection device within the housing, and collects emissions generated during the filling, melting/refining, and tapping stages. Enhanced by selectively controlling the exhaust of pollutants. Selective control of the exhaust of contaminants is accomplished by utilizing a series of interconnected dampers positioned within the exhaust system.

Arc furnace systems typically have a first support on which is mounted a tiltable, fully filled furnace vessel. The furnace system includes equipment for filling the furnace vessel in an opening adjacent to the furnace vessel and a pouring spout defining a tapping opening adjacent to the furnace vessel. A second support, continuous with the first support, supports a device for collecting molten metal and refined metal at the tap point.

Emissions generated during the multiple operating stages of the furnace are collected in the furnace by generally enclosing the furnace system and collection system within a housing and bringing the housing into sealing engagement with the first and second supports, as described above. This is effectively collected by providing the housing with an upper area defining an empty space. Selective collection of the emissions generated during each stage of furnace operation is achieved by installing a first exhaust device in the upper area of the housing (near J and a second) F exhaust device adjacent to the tap opening. This is done by providing. The first and second exhaust devices have a common Jul'
connected to the output device. A third exhaust system, such as a fourth hole or side draft exhaust system, is preferably connected to a common exhaust system for exhausting fumes generated during the melting and refining stages. Control dampers associated with multiple evacuation devices and a common evacuation device can be used for filling stages in their individual locations, melting/111? They are interconnected to be alternately opened and constricted for the purpose of selectively venting waste generated during the cracking or tapping stage.

It will be appreciated from this brief description that the present invention collects the fumes generated during all operating phases of the furnace, without the need for additional fume loudspeakers at various fume generating points. Moreover, the selective evacuation of the fume by an interconnected controlled damper device reduces the amount of air mixed with the dyeing fume, while this reduces the amount of gas that must be subsequently cleaned. and thus eliminates the need for large and expensive cleaning systems. in the end.

The present invention eliminates the need to evacuate the plant during if, if cleaning operations and solves many of the health-related problems associated with prior art methods.

The foregoing summary as well as the following detailed description of the preferred embodiments of the invention are unclear in view of the accompanying drawings.
You will understand it better by reading the book l.

Among the arc furnaces illustrated in FIGS. 1 to 5 that can be filled from the top, there is a furnace equipped with a primary container 10 and a device for filling the furnace positioned adjacent to the primary container 10. is best illustrated in FIG. 2 as including a filling bucket 6 that can be moved toward and away from the furnace by a movable frame member 8. The furnace itself includes a rotatable upper part 12 having three electrodes 14 associated with the primary vessel 10. A rotatable top 12 and its associated electrode I4 are installed in the primary vessel 10 to allow rotational movement from the top of the vessel to one side during the furnace filling operation. 1
The next container is positioned on a first support 16 as shown in FIGS. 1 and 2, which support includes an axle 18 that allows the container to be tilted about pivot point 20 during the pouring operation. The pivot point is best illustrated in FIG. The molten and refined material is discharged through a suction spout 22 which defines an oil discharge point adjacent to the furnace. In the present invention, the apparatus for collecting the molten refined material discharged or dispensed from the primary vessel IO through the injection spout 22 includes a ladle 24, which ladle is best illustrated in FIGS. 1 and 2. The movable 1 suspension member 26, which is well illustrated, moves freely towards and away from the oil drain opening. The collection device can overlap or rest on a second support 28 at the point of oil spillage, which support is in continuity with the first support 16 .

The arc furnace described above is of conventional construction and is a source of large amounts of gas and particulate emissions during furnace operation.

The present invention provides a fume control system designed to selectively collect emissions generated during multiple operating stages of a furnace and direct them to a control area. The illustrated embodiment of the fume control system illustrated in FIGS. 1, 2, and 4 includes a housing 30 that covers the top and sides of the furnace, and that covers the entire furnace during all phases of operation. The first support 16 is in sealing engagement with the second support 28 to surround the furnace and collection device, the housing also having an upper region overlapping the furnace vessel to provide open space above the vessel. I will provide a. The upper region of the housing includes a roof portion 32, shown in FIGS. 1 and 2, which defines the upper boundary of the open space of the housing and its combination during furnace filling and IR purging operations. The height is sufficient to allow the rotatable upper part with the electrodes to be moved up and down. The housing also includes walls 34 surrounding the sides of the furnace.
The wall is in sealing engagement with the first support portion 16 and the second support portion 28 and is of sufficient width to permit operation of the furnace during multiple stages of operation of the furnace.

The housing includes movable parts allowing movement of the filling device and the collecting device, the housing including a first charging device for loading the filling bucket 6 into the housing and a collecting ladle 24.
a second loading device for loading into the housing of the housing.

A first charging device provided for charging into the housing of the filling device is a lower portal 80 for the filling bucket 6.
and its combination includes an upper portal 82 for the loading of five movable members 8. The lower portal is open only during movement of the filling bucket, and the upper portal is open during movement of the filling bucket and also when the filling bucket is in the filling position. Inserting the collection device into the housing 1
The second charging device is the lower portal 8 to the ladle 24.
4 and its associated movable: U frame (including the upper portal 86 for No. 26. The lower portal opens only during the movement of the ladle, while the upper portal opens only during the movement of the ladle. The upper and lower portals of the first and second charging devices, respectively, are also opened when the middle and ladle are in the gamma draw-out opening.As best illustrated in FIGS. includes a closing body and a pair of sliding doors which open and close from the center of each portal.As can be seen from FIG. Although not shown, the lower portal 8.1 and the upper portal 86 of the second charging device can likewise be opened and closed by means of a suitable motor arrangement.

As previously discussed, during a filling operation lower portal 80 and upper portal 82 will be opened as filling bucket 6 is moved toward and away from primary vessel 10 of the furnace. During filling, the lower vau lure 0 is closed to minimize fume escape. Since the movable bridge member 8 supports the bucket during filling in addition to moving the filling bucket toward and away from the container, the upper portal 82 must be in an open state during filling.

During the pouring operation, the lower portal B4 and the upper portal 86 are interposed when the ladle 24 moves toward and away from the pouring point. During the tap operation, the lower portal 84 is closed to minimize leakage. The movable 1U frame member 26 not only allows the ladle to be moved toward and away from the take-out portion, but also supports the ladle during the pouring operation, so the upper portal 76 must also be open during the pouring operation. .

Finally, all portals remain closed during f6 melting and refining operations.

The fume control system may also include other closures to the portals described above, including the air curtain device 90 of the present invention. As shown in FIG. 3, an air curtain device 90 is proximate the upper portals of the first and second charging devices.

As shown, the air curtain device directs the flow of air from inside the housing at least across these upper portals to form an air curtain that restricts the flow of fume through the charging device when the respective charging device is open. Flow toward exhaust population 92.

In particular, the air curtain device in combination with the upper portals 82 and 86 restricts the flow of fume through the interposed charging device, especially during filling and tapping operations. The curtain thus acts as an effective closure to prevent the fume from escaping from the housing when the upper portal opens to allow the movable suspension members 8 and 26 to pass.

A device is provided for exhausting fumes generated and released during furnace filling, melting/elliptical and tapping operations. The exhaust system typically includes a conduit having an inlet and a control associated therewith for the purpose of selectively collecting and removing emissions from the housing during all stages of furnace operation at each individual operating opening. It can have a damper.

As best illustrated in FIGS. 1 and 2.

A first exhaust system, including a conduit 40 with an inlet 42 and its associated first control damper 44, is connected to the melting stage and H't
：lI'J Collecting the emitted material in the crotch floor 5rW 1-
If the furnace is not equipped with a separate exhaust system designed to It is a provision.

As shown in FIG. 1, the inlet portion of the first exhaust system can be provided on either side of the portal, particularly the upper port, barrel 82. an inlet 4 associated with the conduit 40 of said first exhaust device;
2 should preferably be located at the end of conduit 40 except above the filling point to effectively capture fumes generated during filling and melting/refining operations.

A second exhaust system including a conduit 50 having an inlet 52 and an associated second control damper 54 is used primarily for the selective removal of emissions generated during tapping operations.
As best illustrated in the figure, it is located adjacent to the hot water outlet. During tapping operation, the furnace with a rotatable top 12 and mating electrodes thereon is operated such that the contents of the furnace are discharged through the injection spout 22 into the ladle 24.
fAJ is done. During the tapping operation, the released bulk effluent flows through the inlet 52 into the conduit 50. A second exhaust system can be similarly positioned on either side of the portal, particularly the lower portal 84. Conduit 5 of the second exhaust device
The inlet 52 associated with the
9) The lower part of the conduit 50 should be located for the purpose of capturing the fume discharged into the 9) J-bend.

The inlets 42 and 52 are offset from the primary vessel 10 of the furnace to provide access by the filler brush, trowel and ladle 24, but are not effective in draining contaminants from around the vessel. Sufficient ventilation means exist.

A common exhaust system, including a dedicated pipe 60, connects the first exhaust system and the second exhaust system and is operable continuously to alternately exhaust emissions from the individual openings. The common exhaust system can have a third controlled damper 62 associated therewith, as best illustrated in FIGS. 1 and 4.

A third, separate exhaust system can be provided to capture the bulk emissions generated during furnace melting and refining operations. FIGS. 1, 2, and 4 illustrate one type of independent exhaust system commonly known in the prior art as a four-hole exhaust system. This fourth hole exhaust system has a fourth hole 60. The conduit 72 includes an inlet in the furnace and an outlet connected to a common discharge device at a point downstream from the third control damper 62 and can have a fourth control damper 74 associated therewith. .

Although the fourth hole system is shown and described in the drawings as a preferred embodiment of a third independent exhaust system, the present invention is not limited thereto, and may be used with other independent exhaust systems, such as side draft exhaust systems. It should be understood that various embodiments can be made to include.

The housing is also provided with a series of fixed windows 94.

During the various operating phases of the furnace, the fume is constantly evacuated, resulting in a negative pressure condition in the housing, so that the fixed gate allows factory air to flow into the housing and replace the air being evacuated with the fume. . It can be seen that the inlets 42 and 52 cooperate with the fixed gate 94 to scavenge fume from the housing. The door is preferably mounted on the side wall 34 of the housing so as not to obstruct the exhaust of the fume at a number of working points and to direct fresh air from the factory across the first support 16 to the inlet 52. It is best positioned in the lower region of the side wall as shown in FIG. 1 so that it can be swept oppositely and directed toward the inlet 42 along the rotatable top 12 which is the inlet of the furnace.

A device is provided for energizing the multiple control dampers described above in cooperation with the operating stages of the furnace.

A controller 56, illustrated in the schematic diagram of FIG. 5, responds to the operation of the furnace controller, shown at 58, by opening the first exhaust system and throttling the second exhaust system during furnace filling. The first exhaust device is throttled during hot water pouring operation.

The first control damper 44 and the second control damper 54 are interconnected to open the second exhaust system. Preferably, the first control damper 44 is partially open while the second control damper 64 is fully throttled during melting and refining operations.

Primarily during furnace filling and tapping operations, if the fume control system includes an independent exhaust system designed to capture emissions generated during the melting and cracking stages. Open the common discharge device and melt 1
The control device 56 can also interconnect the third control damper 62, the first control damper 44, and the second control damper 54, respectively, so as to throttle the υU output device through the J during the %J+ and refining operations. .

The otherwise common exhaust system remains open during all operating phases of the furnace.

Finally, during the melt operation and the fine $V operation, the third independent
A control device 56 controls the first, second, . The third and fourth control dampers can be interconnected.

The overall effect of the control device 56 interconnecting the control dampers is to selectively evacuate fume from within the housing at the location where the fume is generated. Selective evacuation of the furnace fume according to the invention minimizes gas retention, which volume must then be cleaned before being discharged to the atmosphere.

1st. Second. A schematic diagram of a control device 56 interconnecting the third and fourth control dampers is illustrated in FIG. The controller is illustrated as being responsive to the furnace filling operation, purification operation, and tapping operation, indicated at 58. FIG. 5 shows a furnace in which the first control damper 44 and the fourth control damper 74 are completely throttled, the 211i1J control damper 54 is fully opened, and the third control damper 62 is fully opened or partially throttled. The configuration of damper control during pumping is particularly illustrated. Also illustrated in FIG. 5 are an emergency bleed-in air system 96 and a suction device, such as a fan 98, which draws the fume from the housing to the first. The exhaust is vented through the second and third exhaust systems into any suitable precipitator, such as the hack house 100.

Without departing from the technical idea of the present invention, the fume system in system may be selected from other melting furnaces such as dielectric furnaces.
It is possible to change and modify it so that it exhausts like R. Therefore,
While a humidifier system for an arc furnace has been illustrated and described as a preferred embodiment of the invention, there may be no departing from the spirit of the invention within the scope of the invention as defined in the following claims. It should be understood that various changes, modifications and substitutions may be made to the preferred embodiment.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an arc furnace and fume control system constructed in accordance with the present invention, with a portion of the housing cut away to illustrate portions of the exhaust system. FIG. 2 is a cross-sectional view of the arc furnace and fume control system taken adjacent the end wall shown in FIG. 1, with the furnace including a fill bucket adjacent the housing. FIG. 3 is a partial cross-sectional view of the air curtain device taken along line 3--3 in FIG. FIG. 4 is a plan view of the arc furnace and fume control system shown in FIG. 1. FIG. 5 is a schematic diagram of a fume control system illustrating the overall control of the collection of emissions from a furnace in accordance with the present invention. 6: Filling bucket 10: Primary container 16: First support part 24: Ladle 28: Second support part 30: Housing 40: Conduit 42: Inlet 44: First control damper
50: Conduit 52: Inlet 54: Second control damper 5
6: Control device 60: Conduit FIG, 5 ■, Incident display Patent application No. 59-2021263.
Relationship to the old case of sleeve straightening Applicant name: Fret Akceborag 4, agent

Claims (1)

[Claims] 1) a first support part (16), a primary container (10) installed on the first support part (16), which is a container of a furnace that can be tilted and can be filled from above; A filling bucket (6) for filling the primary container (10), which is the furnace container, located at a filling location adjacent to the furnace, a tapping portion adjacent to the furnace, and the first support portion (
a second support (28) adjacent to the furnace vessel (16), a collection device arranged over the second support at the tapping point for collecting molten refined metal from the primary furnace vessel (10); 1. A fume control system suitable for a furnace comprising: (a) a top and side surface of the furnace in sealing engagement with the first and second supports (16, 28); (b) a housing (30) having an upper region adapted to enclose the furnace and collection device ladle (24) in its entirety and defining an open space overlying the furnace; (c) a first exhaust conduit (40) having an inlet (42) in said open space adjacent to the upper region and having an associated first control damper (44); Inlet (5
2) a second exhaust conduit (50) in combination with a second control damper (54); and (d) a common exhaust conduit (40, 50) connected to said first and second exhaust conduits (40, 50). (e) opening the first evacuation device conduit (40) during filling and constricting the second evacuation device conduit (50) and operating the first evacuation device during pouring; The first control damper (44) and the second control damper (54) are interconnected to throttle the conduit (40) and open the second exhaust conduit (50), thus opening the common exhaust conduit. A fume control system characterized in that (60) comprises a control device (56) continuously operable to evacuate fumes alternately from individual locations. 2) A collecting ladle (24) in which the filling device comprises a filling bucket (6) movable toward and away from the filling point, and the collecting device includes a collecting ladle (24) movable toward and away from the tapping point. a first charging device (80), the housing comprising a movable part for enabling the movement of the filling device, and the collecting device for charging the filling bucket (6) into the housing. , 82) and a second collecting ladle (24) for loading into the housing.
charging devices (84, 86), directing a flow of air from within the housing to form an air curtain that controls the flow of fume through the charging device when the respective charging device is open; an air curtain device (90) adjacent said first charging device (80, 82) and said second charging device (84, 86) to flow across said first and second charging devices;
2. A fume control system for a furnace as claimed in claim 1, wherein said system includes: a fume control system for a furnace; 3) the filling device includes a movable suspension member (8) for moving the bucket (6), the first charging device providing a lower portal (80) for the filling bucket and an upper portal (82) for the suspension member; the lower portal being open only during the movement of the bucket (6) into and out of the housing, and the upper portal being open during the movement of the bucket and whenever the bucket is within the housing. Store the suspension members,
Fume control system for a furnace according to claim 2, characterized in that the air curtain device (90) is associated with the upper portal (82) of the first charging device. 4) the collection device includes a movable suspension member (26) for moving the ladle (24), and the second loading device includes a lower portal (84) for the collection ladle and an upper portal (84) for the suspension member; 86), wherein the lower portal (84) is opened only during the movement of the ladle into and out of the housing, and the lower portal (76) is opened only during the movement of the ladle and when the ladle is in the housing. Claim 2, characterized in that the air curtain device (90) is open at any time to accommodate the suspension member, and that the air curtain device (90) is associated with the upper portal of the second charging device. and a fume control system for a furnace according to paragraph 3. 5) a third control damper (62) positioned within said common exhaust system, opening said common exhaust system during filling and tapping operations, and opening said common exhaust system between tapping and filling operations; said first control damper (44), second control damper (54) and third control damper (62) to
A fume control system for a furnace according to each of the above items, characterized in that the fume control system for a furnace is provided with the control device (56) that interconnects the fume control system. 6) a third exhaust gas having an inlet connected to the furnace and an outlet connected to the common exhaust device downstream from the third control damper for exhausting fumes generated in the furnace during melting and refining operations; Apparatus (70, 72), said third exhaust system and said first, second and third exhaust systems for opening said third exhaust system during melting and refining operations and throttling said third exhaust system during filling and tapping operations; Claim 5, characterized in that it has a fourth control damper (74) associated with said control device (56) interconnecting a fourth control damper (74) to a third control damper. Fume control system for the furnace described. 7) The furnace is an arc furnace, and the third exhaust device is a fourth exhaust device.
7. A fume control system for a furnace as claimed in claim 6, characterized in that it is a hole exhaust system. 8) The furnace and the control device (56) are connected, such that the first and third control dampers are opened during the filling operation and the second and fourth control dampers are throttled, and the control device (56) is connected during the tapping operation. The second and third control dampers are opened, the first and fourth control dampers are throttled, and during melting and refining operations, the fourth control damper is opened and the first, second and third control dampers are throttled. 7. A fume control system for a furnace according to claim 6, characterized in that the fume control system for a furnace is throttled. 9) a fixed hood (94) on said housing for allowing air to enter from outside said housing and cooperating with said inlets of said first and second exhaust devices for scavenging fumes from said housing; A fume control system for a furnace as described in each of the above items. 10) A furnace comprising the fume control system described in each of the above items.